Dimension

Dimension tokens carry a number and a unit. They are the workhorse type: spacing, radii, sizes, border widths, and type metrics are all dimensions.

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Value format

{ "$type": "dimension", "$value": { "value": 16, "unit": "px" } }

Field	Allowed
value	Any finite number, including negative
unit	"px" or "rem" — nothing else

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What you can type

Input	Stored as
16px	{ value: 16, unit: "px" }
1.5rem	{ value: 1.5, unit: "rem" }
16	{ value: 16, unit: "px" } — a bare number defaults to px
-2px	{ value: -2, unit: "px" }
{global.space.md}	A reference

em, %, vh, pt and every other CSS unit are rejected. This is strict DTCG: the specification defines exactly two units so that a token is unambiguous outside a CSS context.

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Applying to Figma

Default target: Size (all).

Group	Targets
Sizing	All, width, height, min width, max width, min height, max height
Border radius	All corners, top-left, top-right, bottom-right, bottom-left
Border width	All sides, top, right, bottom, left
Spacing	Padding (all + each side), gap, counter-axis gap
Typography	Font size, letter spacing, line height — text layers only
Effects	Shadow offset X, offset Y, blur radius, spread

rem → px conversion

Figma has no notion of a root font size, so a rem value is multiplied by a fixed base of 16 when applied. 1.5rem sets 24. The stored token keeps rem, so export is unaffected.

This base is not configurable.

Silent no-ops

If the target property does not exist on the selected layer — a corner radius on a line, padding on a non-auto-layout frame — the apply is skipped without an error. Check the result before assuming it landed.

The effects targets are the exception: they modify the first drop or inner shadow and fail loudly with “add a drop or inner shadow first” if there is none.

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Notes and limits

• Applying a dimension to letter spacing or line height forces the unit to pixels in Figma, even if the layer was using a percentage.
• dimension cannot be applied to opacity or rotation — use a number token for those.
• When exported to a Figma Variable, only a "16px"-style string is parsed; the DTCG object form is passed through unchanged. See Figma Variables.